Submitted to: Proceedings of the Entomological Society of Washington
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/2/1999
Publication Date: N/A
Interpretive Summary: Scale insects are common pests of blueberries in the United States. One of the most important pests in blueberries in New Jersey is the Putnam scale, but the life history is poorly understood. This research monitored the development of the species through a yearly cycle and demonstrated that the information used by farmers and pest management specialists was incorrect in several ways. The pest has two generations each year rather than one and overwinters as immatures rather than adults as previously thought. This information is important in the development of pest management strategies and will be helpful to farmers, biological control experts, and pest management personnel.
Technical Abstract: Life history of the Putnam scale was investigated during 1997 and 1998 on highbush blueberries in the pine barrens of Southern New Jersey. Putnam scale has two generations each year. Crawler emergences in the first and second generations peaked during late May and early to mid August, respectively. This species overwinters as second instar nymphs, primarily under the bark (cork cambium) of the host. Adult females that occur on or under the bark of blueberries differ morphologically from those on the leaves and fruit. Descriptions of both forms are provided. Nine species of parasitoids were reared from the canes containing Putnam scale infestations and the peak emergence times of the parasitoids coincided with the transition between the adult females and crawlers.